The present invention relates to a fuel tank system including a plurality of tanks.
U.S. Pat. No. 5,983,932 discloses a fuel tank system equipped with an onboard refueling vapor recovery (ORVR) system. An ORVR system collects fuel vapor in the tank using a canister by discharging the fuel vapor in the tank through the canister at the time of refueling, thereby limiting the discharge of fuel vapor to the outside.
The fuel tank system is equipped with an auxiliary tank in addition to the main tank, which accommodates a pump for drawing fuel. The fuel tank system has a balance pipe connecting the lower part of the main tank and the lower part of the auxiliary tank. The liquid level of fuel in the auxiliary tank thus changes with changes in the liquid level of fuel in the main tank due to refueling of the main tank and drawing of the fuel from the main tank by the pump. Accordingly, the liquid levels of the tanks are equalized.
In the above-described fuel tank system, the balance pipe is provided so as to traverse the space between the two tanks. Therefore, when the fuel system is installed in a vehicle, it is difficult to arrange the two tanks at positions sandwiching elongated parts such as the exhaust pipe or the propeller shaft, which may make it impossible to employ the fuel system in some cases.